make LTP version check a blacklist

Author: m6w6

configure.in

@@ -784,7 +784,12 @@ if test "$PHP_GCOV" = "yes"; then
     AC_MSG_ERROR([ccache must be disabled when --enable-gcov option is used. You can disable ccache by setting environment variable CCACHE_DISABLE=1.])
   fi
 
-  ltp_version_list="1.5 1.6 1.7 1.9 1.10"
+  dnl min: 1.5 (i.e. 105, major * 100 + minor for easier comparison)
+  ltp_version_min="105"
+  dnl non-working versions, e.g. "1.8 1.18";
+  dnl remove "none" when introducing the first incompatible LTP version an 
+  dnl separate any following additions by spaces
+  ltp_version_exclude="1.8"
 
   AC_CHECK_PROG(LTP, lcov, lcov)
   AC_CHECK_PROG(LTP_GENHTML, genhtml, genhtml)
@@ -794,21 +799,30 @@ if test "$PHP_GCOV" = "yes"; then
   if test "$LTP"; then
     AC_CACHE_CHECK([for ltp version], php_cv_ltp_version, [
       php_cv_ltp_version=invalid
-      ltp_version=`$LTP -v 2>/dev/null | $SED -e 's/^.* //'`
-      for ltp_check_version in $ltp_version_list; do
-        if test "$ltp_version" = "$ltp_check_version"; then
-          php_cv_ltp_version="$ltp_check_version (ok)"
+      ltp_version_vars=`$LTP -v 2>/dev/null | $SED -e 's/^.* //' -e 's/\./ /g' | tr -d a-z`
+      if test -n "$ltp_version_vars"; then
+        set $ltp_version_vars
+        ltp_version="${1}.${2}"
+        ltp_version_num="`expr ${1} \* 100 + ${2}`"
+        if test $ltp_version_num -ge $ltp_version_min; then
+          php_cv_ltp_version="$ltp_version (ok)"
+          for ltp_check_version in $ltp_version_exclude; do
+            if test "$ltp_version" = "$ltp_check_version"; then
+              php_cv_ltp_version=invalid
+              break
+            fi
+          done
         fi
-      done
+      fi
     ])
   else
-    ltp_msg="To enable code coverage reporting you must have one of the following LTP versions installed: $ltp_version_list"      
+    ltp_msg="To enable code coverage reporting you must have LTP installed"      
     AC_MSG_ERROR([$ltp_msg])
   fi
 
   case $php_cv_ltp_version in
     ""|invalid[)]
-      ltp_msg="You must have one of the following versions of LTP: $ltp_version_list (found: $ltp_version)."
+      ltp_msg="This LTP version is not supported (found: $ltp_version, min: $ltp_version_min, excluded: $ltp_version_exclude)."
       AC_MSG_ERROR([$ltp_msg])
       LTP="exit 0;"
       ;;